Generally, communication systems have been introduced which integrate wireless communication networks, such as a personal communication system (PCS), with existing wireline communication networks. In such systems, structure is provided for interfacing the capabilities of a land line telephone system with a radio link communications system, and to control the provision of private network service features for users of both radio link systems and land line systems. Call processing data associated with each subscriber is stored in a central service control point, or database, within the network. Call routing to either a land line or a wireless unit is controlled by a mobile controller network element in conjunction with the central database. Known systems can typically support all the services unique to each of the wireline telephone network and the wireless network using a single directory number and a central database.
However, efficiency in call routing for such integrated systems is directly dependent upon whether the wireline class 5 switch has an established access connection to an access manager or controller to which a destination wireless unit is currently registered. More specifically, because a single directory number is employed in known systems, calls to a wireless subscriber are routed to an associated wireline switch. The problem encountered with such arrangements is that if the associated wireline does not have an access connection to an access controller currently serving the intended wireless subscriber, an interoffice call over interoffice trunk lines must be set up to forward the call to a wireline switch which does have access to the serving access controller. Setting up of such an interoffice call adds delay to the call routing process, thereby decreasing system efficiency. In addition, since wireless systems typically incur additional cost charges for connecting wireline switches and trunk lines to route calls, the use of interoffice trunk lines to route calls also adds to a wireless system's operational costs.
Therefore, a needs exists for a call routing arrangement which supports wireless extension in an integrated wireline and wireless communication system which reduces the need for interoffice calls.